Why Ecology Matters CH. 1 Flashcards
What limits distribution of species?
climate and geography (humans are now moving species into new regions though)
How is climate change changing distributions of species?
moving polewards but not with all species
What prevents dispersal movements?
Barriers.
ex. Penguins can live in Chicago but are prevented from moving there themselves because of the tropical oceans which block them
How can you tell if distribution is limited by lack of dispersal?
Transplant studies. Move organism to new area, see if the organism survives. Survival = barrier exists
Most of the crops we grow…
were inadvertent transplant studies
European starling
Deliberately introduced for some reason. Became a huge pest, bold, aggressive, attacks fruit crops, has displaced several native bird species.
Cane toad
introduced to control bug that eats sugar cane. Failed spectacularly. Cane toad is a huge pest now. They’ve figured out that they breed in ponds and a control strategy is to eliminate these watering holes at critical times in critical areas. No native predator species went extinct as a result (toad is highly poisonous).
What increases the likelihood a transplant study/ species introduction will succeed?
Generally, if more individuals of a species are introduced (increases survivorship and colonization rates). Exceptions are sambar deer and himalayan tahr. Small populations are more prone to fluctuations due to bad weather or predator attacks.
four major steps of invasion process
- transport
- establishment
- spread
- impact
Process can fail at any one of these steps
- transport can fail because either the biological environment may eliminate the newcomer or the physical- chemical environment may be lethal/prevent reproduction
- predators may prevent establishment (mussels are eaten by starfish in protected water)
Where does penicillin come from?
soil fungus penicillium secretes this antibiotic.
Where will stream fish move as temps rise?
upstream to stay within temperature zone
Example of species moving polewards
Mangrove trees, as sea temperatures rise (temp. thresholds)